<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			#box {
				height: 400px;
				width: 270px;
				background: gray;
				color: white;
				text-align: center;
				margin: auto;
			}
			#aa{
				display: none;
			}
			#xinxi{
				font-size: 18px;
			}
			#tz{
				font-size: 23px;
			}
		</style>
	</head>

	<body>
		<div id="box">
			<div id="xinxi">
				<span id="tz">通知通告/</span>
				<span id="zb">招标公告</span>
			</div>
			<div id="nr">
				<p id="qq">
					qqqqqqqqqeeeeeeeeerrrrrrrr
				</p>
				<p id="aa">
					aaaaaaaaassssssssddddddddd
				</p>
			</div>
		</div>
		<script type="text/javascript">
			var tz=document.getElementById('tz');
			var zb=document.getElementById('zb');
			var qq=document.getElementById('qq');
			var aa=document.getElementById('aa');
			tz.onmouseover=function(){
				tz.style.fontSize='23px';
				zb.style.fontSize='18px';
				qq.style.display='block';
				aa.style.display='none';
			}
			zb.onmouseover=function(){
				zb.style.fontSize='23px';
				tz.style.fontSize='18px';
				aa.style.display='block';
				qq.style.display='none';
			}
		</script>
	</body>

</html>